Proposition: how much you should prioritize using currently available life extension methods depends heavily on how highly you value arbitrary life extension. The exponential progress of technology means that on the small chance a healthier lifestyle* nontrivially increases your lifespan, there is a fairly good chance you get arbitrary life extension a result. So the outcome is pretty binary - live forever or get an extra few months. If you're content with current lifespans, as most people seem to be, the chance at immortality is probably still small enough to ignore.

*healthier than the obvious (exercise, don't smoke, etc.)